<template>
<div id="root">
  <div class="todo-container">
    <div class="todo-wrap">
      <my-header @addTodo='addTodo'/>
      <my-list :todos='todos'/>
      <my-footer :todos='todos' @clearTodo='clearTodo'/>
    </div>
  </div>
</div>
</template>

<script>
import MyHeader from './components/MyHeader.vue'
import MyList from './components/MyList.vue'
import MyFooter from './components/MyFooter.vue'

export default {
  name: 'App',
  components: {
    MyHeader,MyList,MyFooter
  },
  data() {
    //由于todos是MyHeader组件和MyFooter组件都在使用，所以放在App中（状态提升）
    return {
      todos:JSON.parse(localStorage.getItem('todos'))||[]
    }
    },
  methods: {
    //添加一个todo
    addTodo(todoObj){
      this.todos.unshift(todoObj)
    },
   //勾选or取消勾选一个todo
			checkTodo(id){
				this.todos.forEach((todo)=>{
					if(todo.id === id) todo.done = !todo.done
				})
			},
      updateTodo(id,title){
				this.todos.forEach((todo)=>{
					if(todo.id === id) todo.title = title
				})
			},
			//删除一个todo
			deleteTodo(id){
				this.todos = this.todos.filter( todo => todo.id !== id )
			},
      //全选or取消全选
      checkAllTodo(done){
        this.todos.forEach((todo)=>{
          todo.done=done
        })
      },
      //清除已完成
      clearTodo(){
        this.todos=this.todos.filter((todo)=>{
          return !todo.done
        })
      },
  },
  watch:{
    todos:{
      deep:true,
      handler(value){
        localStorage.setItem('todos',JSON.stringify(value))
      }
    }
  },
  mounted() {
    this.$bus.$on('checkTodo',this.checkTodo)
    this.$bus.$on('deleteTodo',this.deleteTodo)
    this.$bus.$on('checkAllTodo',this.checkAllTodo)
    this.$bus.$on('updateTodo',this.updateTodo)
  },
  beforeDestroy() {
    this.$bus.$off('checkTodo')
		this.$bus.$off('deleteTodo')
		this.$bus.$off('checkAllTodo')
		this.$bus.$off('updateTodo')
  },
}
</script>

<style lang="css" scoped>
/* base */
body {
  background: #fff;
}
.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
.btn {
  display:inline-block;
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}
.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}

.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}

.btn:focus {
  outline: none;
}

</style>>
